The ratio of the number of red stickers to green stickers is 2 : 1.
After Adam buys another 40 red stickers and 50 green stickers,
the ratio becomes of the number of red stickers to green stickers is 8 : 7.
How many stickers does Adam have now?
|
Make p the same (1) x 7 = (3) |
(1) Red |
(2) Green |
Make p the same (2) x 8 = (4) |
Before |
14 u |
2 u |
1 u |
8 u |
Change |
+ 280 |
+ 40 |
+ 50 |
+ 400 |
After |
14 u + 280 |
2 u + 40 |
1 u + 50 |
8 u + 400 |
Comparing the red stickers and the green stickers in the end |
56 p |
8 p |
7 p |
56 p |
2 u + 40 = 8 p --- (1)
1 u + 50 = 7 p --- (2)
Make p the same by using the LCM of 7 and 8.
LCM of 7 and 8 is 56.
(1)
x 7 14 u + 280 = 56 p --- (3)
(2)
x 8 8 u + 400 = 56 p --- (4)
(3) = (4)
14 u + 280 = 8 u + 400
14 u - 8 u = 400 - 280
6 u = 120
1 u = 120 ÷ 6 = 20
Number of stickers that Adam has now
= 2 u + 40 + 1 u + 50
= 2 u + 1 u + 40 + 50
= 3 u + 90
= 3 x 20 + 90
= 60 + 90
= 150
Answer(s): 150